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Reception device, reception method and integrated circuit

a reception device and integrated circuit technology, applied in the field of orthogonal frequency division multiplexing modulated digital broadcasting reception devices, can solve the problems of deteriorating reception performance and generation of interpolation errors in equalization sections b>309/b>, and achieve the effect of preventing deterioration of reception performan

Inactive Publication Date: 2013-01-15
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0034]As described above, according to the present invention, it becomes possible to provide an OFDM-modulated digital broadcasting reception device capable of preventing a reception performance from deteriorating as a result of an equalization section which malfunctions due to the discrete gain fluctuation caused by the stepped AGC.

Problems solved by technology

However, the communication device 300 has a problem in that an interpolation error, which is to be described below, occurs in the equalization process executed by the equalization section 309. FIG. 12 is a diagram describing the equalization process executed by the equalization section 309. FIG. 12(b) is an image in which N−6th to Nth symbols of a received OFDM signal are chronologically represented.
As a result, a demodulation error of the OFDM signal is generated, thereby resulting in deterioration of the reception performance.
As described with reference to FIG. 12, however, the equalization section 309 generates an interpolation error due to a gain variation caused by the stepped AGC control when the time axis interpolation is performed.

Method used

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  • Reception device, reception method and integrated circuit
  • Reception device, reception method and integrated circuit
  • Reception device, reception method and integrated circuit

Examples

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first embodiment

[0082]FIG. 1 is a diagram illustrating an exemplary structure of an OFDM-modulated digital broadcasting reception device 100 according to a first embodiment of the present invention. As shown in FIG. 1, the structure of the OFDM-modulated digital broadcasting reception device 100 (hereinafter referred to as the reception device 100) is basically the same as that of the conventional reception device 300 shown in FIG. 13 in that the timing control section 306 and the equalization section 309 are replaced with a timing control section 6 and an equalization section 9, respectively. A structure of the equalization section 9 is basically the same as that of the equalization section 309 in that a transmission path coefficient correction section 23 is additionally provided and the time axis interpolation section 324 is replaced with a time axis interpolation section 24. Note that the same components of the reception device 100 as those of the conventional reception device 300 will be denote...

second embodiment

[0102]In the reception device 100 according to the first embodiment, an error may be generated in the equalization process executed by the equalization section 9 when a phase of an OFDM signal is significantly varied by the stepped AGC. This is because a phase variation amount is generally large when a gain step width of the gain variable amplifier included in the tuner 302 is also large, and it is difficult to design the gain variable amplifier so as to reduce the deviation of the phase variation amount to a preset value or less.

[0103]An OFDM-modulated digital broadcasting reception device 200 (hereinafter referred to as a reception device 200) according to a second embodiment of the present invention does not perform a time axis interpolation when a phase variation is large at a time when the gain is varied by the stepped AGC, thereby avoiding the problem of the reception device 100.

[0104]FIG. 4 is a diagram illustrating an exemplary structure of the OFDM-modulated digital broadca...

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Abstract

A reception device for receiving an OFDM signal whose level is maintained constant by performing an AGC control which adjusts an amplification gain by means of a discrete gain value includes an equalization section operable to execute an equalization process of detecting, respectively, distortions of a plurality of reference subcarriers regularly included in the OFDM signal on which the fast Fourier transform has been performed, and of estimating, by means of an interpolation using the detected distortions, a distortion of the OFDM signal, which distortion is caused by transmission path propagation so as to correct the estimated distortion of the OFDM signal, and the equalization section corrects, by using the AGC control signal, an estimated error of the distortion of the OFDM signal, which distortion is caused by a discrete amplification gain variation of the OFDM signal.

Description

TECHNICAL FIELD[0001]The present invention relates to an OFDM (Orthogonal Frequency Division Multiplexing) modulated digital broadcasting reception device using a stepped AGC (Automatic Gain Control) which varies a gain of an amplifier in a stepped manner.BACKGROUND ART[0002]A function of automatically adjusting an amplification gain of an amplifier is referred to as an AGC. Further, a type of the AGC which adjusts a gain by varying the amplification gain in a stepped manner (discretely) is referred to as a stepped AGC. In some cases, the stepped AGC is applied in an OFDM-modulated digital broadcasting reception device for receiving digital broadcasting based on standards such as an ISDB-T (Integrated Service Digital Broadcasting Terrestrial) and a DVB-T (Digital Video Broadcasting Terrestrial).[0003]FIG. 8 is a diagram illustrating an exemplary structure of a conventional OFDM-modulated digital broadcasting reception device 300 that performs the stepped AGC (hereinafter referred to...

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): H04K1/10
CPCH03G3/3078H04L25/0232H04L25/03159H04L27/2647H04L2025/03522
Inventor KANNO, IPPEI
Owner PANASONIC CORP